DESCRIPTION (Adapted from Applicants Abstract): This proposal is for work to further develop and characterize three dielectrophoretic cell separators for use with T-lymphocytes, B-leukocytes, monocytes, and granulocytes. The dielectrophoretic cell separation approach depends on alternating current (AC) electrokinetic phenomena which induce forces on cells that are dependent on cell composition, cell surface geometry. Three separator strategies will be explored: i) based on dielectric affinity, ii) dielectrophoresis combined with field flow fractionation, and iii) two dimensional dielectrophoresis in a traveling wave configuration.